Laminitis Research Group Still Recruiting Cases (AAEP 2012)

In a recent survey of American Association of Equine Practitioners (AAEP) members, 65% reported that laminitis is at the top of their list of conditions requiring more research and understanding. In 2000 the USDA Animal and Plant Health Inspection Service estimated that 13% of U.S. horse operations deal with horses affected by laminitis annually and that the condition impacts approximately 2% of U.S. horses each year. A report at the 2009 AAEP Foundation Equine Laminitis Research Workshop estimated that 15% of horses will develop laminitis during their lifetimes. In other words, equine veterinarians are not just imagining that this is a significant issue.

At the 2012 AAEP Convention, held Dec. 1-5 in Anaheim, Calif., Michelle Coleman, DVM, Dipl. ACVIM, of Texas A&M College of Veterinary Medicine, described an epidemiologic study in which researchers are examining pasture and endocrinopathy-associated laminitis (PEAL). Up until now, most laminitis study models have been based on experimental induction of this disease. This current PEAL study is designed to evaluate patient-based cases of owner-managed horses, making it extremely relevant to studying spontaneous occurrence of laminitis.

The investigators are comparing healthy controls and lameness controls with no history of laminitis to animals that have developed laminitis within the previous four weeks; the laminitis cases studied (also referred to as index cases) cannot be caused by sepsis, grain overload, or excess weight bearing. For a horse to qualify for study inclusion, he must be at least Obel Grade 2 lame (moves willingly at a walk and trot but with a noticeably shortened and stabbing stride; a foot can be lifted off the ground without difficulty) and exhibit at least two of the following characteristics: sensitivity to hoof testers, a foundered stance, radiographic (X ray) evidence of thickened laminae, and no history of prior laminitis or other lameness. The healthy control horses must live on different premises than the index cases. Similarly, the lame controls must live on different premises than the index cases and have a history of being Grade 3 lame (at a trot on a straight line) in one forelimb for no more than four weeks.

"The objective is to identify characteristics particular to laminitis cases," said Coleman. The researchers are also collecting pertinent information about each horse, including breed and age, housing and management, activity type and level, hoof care, nutrition, pasture exposure, pasture characteristics, physiological factors (body condition, pregnancy, lactation, medication administered, as examples), and history of recent transportation.

Researchers are still actively recruiting cases. To participate in the study, equine veterinarians must register at Texas A&M Veterinary Medical Center with Coleman or Noah Cohen, VMD, MPH, PhD, Dipl. ACVIM. They then receive a study kit, identify a case and appropriate controls, and collect the required data and samples to be sent to the study researchers at Texas A&M. To date, investigators had collected 70 cases with 55 healthy controls and 40 lameness controls; the research team's goal is to investigate 400 cases with 800 controls.

Coleman stressed the importance of this study: "It is based on natural disease with the powerful resource of using practitioner-collected data. All equine practitioners are invited to participate. The overall objective is to direct the future of laminitis research with the ultimate goal of controlling or preventing laminitis." Owners of horses with laminitis are encouraged to speak with their veterinarian about registering to be included in the study.